A known image acquisition device in the related art includes two image acquisition elements and splits light from a subject so as to acquire two kinds of images by means of the two image acquisition elements (for example, see Patent Literature 1).
This image acquisition device splits a light beam by using an optical-path splitting means, such as a half mirror, and acquires two kinds of images at different magnifications simultaneously by using the two image acquisition elements. Another type of image acquisition device switches between optical paths of a light beam by using an optical-path switching means and acquires an image by using one of two image acquisition elements.